Edit: Ugh, I totally just realized that I spelled my own word wrong. FAIL. :)
1. Obtained, done, or made by clandestine or stealthy means.
2. Acting with or marked by stealth.
Of course when thinking of stealth the first thing that comes to my mind is ninjas:
(please excuse the crap angle. It was the only way I could avoid the glare. Then it wasn't square to crop. Oh well.)